yang/yang-model-util/src/main/java/org/opendaylight/yangtools/yang/model/repo/util/InMemorySchemaSourceCache.java

   1 /*
   2  * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
   3  * This program and the accompanying materials are made available under the
   4  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   5  * and is available at http://www.eclipse.org/legal/epl-v10.html
   6  */
   7 package org.opendaylight.yangtools.yang.model.repo.util;
   8
   9 import com.google.common.annotations.Beta;
  10 import com.google.common.base.FinalizablePhantomReference;
  11 import com.google.common.base.FinalizableReferenceQueue;
  12 import com.google.common.cache.Cache;
  13 import com.google.common.cache.CacheBuilder;
  14 import com.google.common.util.concurrent.CheckedFuture;
  15 import com.google.common.util.concurrent.Futures;
  16 import java.util.ArrayList;
  17 import java.util.Collections;
  18 import java.util.List;
  19 import org.opendaylight.yangtools.yang.model.repo.api.MissingSchemaSourceException;
  20 import org.opendaylight.yangtools.yang.model.repo.api.SchemaSourceException;
  21 import org.opendaylight.yangtools.yang.model.repo.api.SchemaSourceRepresentation;
  22 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
  23 import org.opendaylight.yangtools.yang.model.repo.spi.PotentialSchemaSource.Costs;
  24 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistration;
  25 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistry;
  26
  27 @Beta
  28 public class InMemorySchemaSourceCache<T extends SchemaSourceRepresentation> extends AbstractSchemaSourceCache<T> implements AutoCloseable {
  29     private final List<FinalizablePhantomReference<T>> regs = Collections.synchronizedList(new ArrayList<FinalizablePhantomReference<T>>());
  30     private final FinalizableReferenceQueue queue = new FinalizableReferenceQueue();
  31     private final Cache<SourceIdentifier, T> cache;
  32
  33     protected InMemorySchemaSourceCache(final SchemaSourceRegistry consumer, final Class<T> representation, final CacheBuilder<Object, Object> builder) {
  34         super(consumer, representation, Costs.IMMEDIATE);
  35         cache = builder.build();
  36     }
  37
  38     public static <R extends SchemaSourceRepresentation> InMemorySchemaSourceCache<R> createSoftCache(final SchemaSourceRegistry consumer, final Class<R> representation) {
  39         return new InMemorySchemaSourceCache<>(consumer, representation, CacheBuilder.newBuilder().softValues());
  40     }
  41
  42     @Override
  43     public CheckedFuture<? extends T, SchemaSourceException> getSource(final SourceIdentifier sourceIdentifier) {
  44         final T present = cache.getIfPresent(sourceIdentifier);
  45         if (present != null) {
  46             return Futures.immediateCheckedFuture(present);
  47         }
  48
  49         return Futures.<T, SchemaSourceException>immediateFailedCheckedFuture(new MissingSchemaSourceException("Source not found", sourceIdentifier));
  50     }
  51
  52     @Override
  53     protected void offer(final T source) {
  54         final T present = cache.getIfPresent(source.getIdentifier());
  55         if (present == null) {
  56             cache.put(source.getIdentifier(), source);
  57
  58             final SchemaSourceRegistration<T> reg = register(source.getIdentifier());
  59             final FinalizablePhantomReference<T> ref = new FinalizablePhantomReference<T>(source, queue) {
  60                 @Override
  61                 public void finalizeReferent() {
  62                     reg.close();
  63                     regs.remove(this);
  64                 }
  65             };
  66
  67             regs.add(ref);
  68         }
  69     }
  70
  71     @Override
  72     public void close() {
  73         while (!regs.isEmpty()) {
  74             final FinalizablePhantomReference<?> ref = regs.get(0);
  75             ref.finalizeReferent();
  76         }
  77
  78         cache.invalidateAll();
  79         queue.close();
  80     }
  81 }